On 8 Aug, 21:53, "Daddy Tadpole" wrote:
All plants need calcium (lime), but some of the ones we particularly like
can't survive with more than trace amounts. We also know that soil that
contains some lime, but not too much, gets depleted if you repeatedly
harvest stuff and don't make good the deficiency.

Hence my question: what plants would most rapidly deplete soil that contains
just a a bit too much lime for rhododendrons and suchlike? A politically
correct approach could be to plant the right kinds of veggies between the
bushes. Possibly someone might be able to propose a more practical approach,
for example a method of preparing batches of low-lime soil.

Regards

Lime in soil is removed by rainwater which is acid due to dissolved
CO2 and by rotted plant material which also is acid.
If the soil is naturally limey (ie the subsoil is limestone or chalk),
then it very gradually subsides and caves are formed.
If the soil sandstone based it will be naturally neutral but rainfall
will make it acid (or rotted plant material) & lime may be needed for
most plants. But it has to be renewed. If it isn't, it will just
revert to it's true nature after a while. I can't think of a way of
accelerating this process.